Ms Terral-Calmes, who has two young children, was stabbed only once, according to reports.

It is believed the mother had psychiatric counselling in the past, and had been accused by police earlier this year of abandoning her 15-year-old son.

Her daughter is now in the care of social services.

Marie-Odile Gay, a member of Education Ministry, said: “This is something that will stay with her forever.

“It's very important to ensure that she is cared for.”

The education minister described told reporters the mother of a pupil "committed this abominable act in a class against a remarkable teacher".

He added: "This July 4, the moment when we should be happy for all children that school is over, that vacations are beginning, that teachers successfully completed the school year, has been turned into a day of mourning ... by this abominable crime.”